This invention relates generally to articulating arms for movably connecting a first body to a second body, specifically to a friction control mechanism for permitting close control of the friction at a joint of an articulating arm, allowing the articulating arm to hold the second body in a set position with respect to the first body after movement.
Articulating arms that extend between a first body and a second body are well known in the art. Dental x-ray machines, for example, often use such articulating arms. The dental x-ray machine often has an x-ray machine head that must be located next to the patient's jaw while in use. Further, it must maintain that position without being held there by an operator, so that the operator can move behind a screen so as to be protected from the x-rays when the machine is operating. When the x-ray machine is not in use, the x-ray machine head must be moved to a location that will not interfere with the rest of the dentist's duties. An articulating arm allows the x-ray machine head to be easily moved between these locations.
Another usage for such articulating arms is to moveably attach a machine to a remote input/output station while maintaining the orientation of the input/output station without being held by an operator. For example, an x-ray machine often has an output screen for providing information to the operator. The operator must be able to see the screen from a remote position where he or she is behind a shield and protected from the effects of the x-rays. The articulating arm maintains the orientation of the screen without being held there by the operator, while allowing the operator use both hands to operate x-ray controls. The operator can move the screen horizontally and vertically to a position where he or she can view it from the remote location. U.S. Pat. No. 6,315,259 issued to Kolb is an example of such an articulating arm.
One problem with existing articulating arms is that they tend to permit drift, so that the piece of equipment being held by the arm loses its set position after the operator moves the equipment to the desired location and releases it. This is a particular problem with articulating arms used with dental x-ray machines. To take dental x-rays, the operator moves the x-ray machine head, attached to an articulating arm, to the desired location next to the patient's jaw, and then must leave the room to activate the x-ray machine. Before the operator is able to activate the x-ray machine, the articulating arm attached to the x-ray machine may lose its set position, causing the x-ray machine head to be in a different position than the operator intended. As a result, an unintended area of the patient's jaw may have been x-rayed, and the operator may have to repeat the x-ray. This wastes both the operator's and the patient's time, as well as potentially exposing the patient to unnecessary x-rays.
This invention relates to improvements to the products described above, and to solutions to some of the problems raised or not solved thereby.